Improvement in rheostats for telegraphic purposes



G. MTTLE.

mprevement in Rheostats for Teegraphic Purposes.

NG. LL Patented Sep. 10, 1872.

....... 4mm 70 Y 7 UNITED STATES PATENT OFFICE.

GEORGE LITTLE, or EUTEEEEOED PARE, NEW JEEsEY.

IMPROVEMENT IN RHEOSTATS FOR TELEGRAPHIC PURPOSES.

Specification of Improvement-s in Rheostat for Telegraphic Purposes, invented by GEORGE LITTLE, of Rutherford Park, Bergen county, New Jersey.

Iheostats have heretofore been employed to regulate the force of the electric current directed into the main line or into a telegraph instrument, and the proportion of that current returned to the battery or to the ground or other connection in the circuit. In these instruments the springs or arms of the adjuster, bearing upon the surface of the helix, and being moved back and forth (often unnecessarily) by the operator, sometimes injure the delicate wires of the helix 5 besides this the surfaces of these wires are exposed to atmospheric induences and the insulation is sometimes rendered imperfect.

My invention consists in a range of separate helices connected to insulated plates or rings in combination with the metallic heads and sliding adjuster, whereby one or more of the said helices can be brought as a resistance into the line to regulate the relative force of branch or shunt circuits.

In the drmving7 Figure l is a vertical section of the/ said rheostat. Fig. 2 is a plan of the same, and Fig. 3 is a cross-section.

In the base a there are introduced wire coils or helices b b, of any desired character and resistance, and the wires from these pass up and connect alternately to the insulated rings c c that are upon a tube or bar of hard wood, cbonite, or other non-conductin g material, that is supported between the heads e and f; or, in place of the rings, plates may be employed upon an insulated bar. The rod h is sustained by the heads e f, but insulated at the head f, and upon this rod 7L is the adjuster 7c, made with prongs or forks l that bear upon the surface of the insulated rings c c or plates. The

battery or line wires are connected at m and n, and the wires at o and i' lead to the instrument 5 or the connections may be made in any of the modes usual where a rheostat is em= ployed. The rst helix b is connected with the head e and with the lirst ring c; the second helix is connected with the iirst and second rings; the third with the second and third, and so on; and the last helix with the last ring and the next to the last; hence, if the adjuster 7c is near the head e, the electricity will pass through all the helices to reach the head f, because the rod h is insulated at the head j', and thereby there would be the entire resistance ot the coils to the circuit between the respective heads, and the circuit would be directed oli' through the line or other wire; and by positioning the adjuster so more or less ot' the helices will be brought into the CIGUU- Vhcn the adjuster is moved coDJgUOHS '0 the head f, then there will be but littlQl'GSS- ance, as the current will pass from the head 6 through the adjuster-rod L and the head f to the binder n. Ilhe lingers of the adjuster are not of the saine length, and will bear upon two rings in passing from one to the next; hence there will not be any interruption in the flow of the current by the act of adjustment. The helices might be placed within the rings and connected, as aforesaid, thereby rendering the apparatus more compact. The return-wire from the instrument may be connected to the head j', as shown, and thence the circuit be completed by an earth-connection 5 or else the return-wire may go direct to the earth-connection, as represented by dotted lines.

I claim as my invention- A series of helices connected to insulated plates or rings, substantially as set forth, in combination with a sliding adjuster, substantially as set forth.

Signed by me this 10th day of July, A. D. 1872.

GEORGE LITTLE.

Witnesses:

GEO. T. PINCKNEY, GHAs. H. SMITH. 

